Dry socket is a very special type of infection after tooth extraction in dentistry, which usually occurs about 3-5 days after tooth extraction and is relatively fixed in time. The reason for this is still undetermined, but it is mainly thought to be related to the fact that the blood clot does not form well after tooth extraction. Because most of the teeth that cause dry socket are mandibular molars, the extraction trauma is large and the corresponding parts of the blood supply is not very good. If the blood clot is not well formed after the tooth is extracted, there will be a void in the extraction wound and necrotic material will appear, with a strong odor. At the same time, the pain will be very intense, for this situation need to go to a professional dentist for further treatment as soon as possible.